The repair of fractured long bones may be accomplished by the attachment of bone plates to the injured bone to hold the opposing fractured sides of the bone in place during healing. Bone plates are generally described as devices with at least one flattened surface and with holes or grooves for screws and/or wires situated in or along the main body of the plate, to allow fixation of the flattened surface of the device to the bone surface. The fixation of the bone plate is intended to hold the bone in place and achieve union of the bone fragments.
In the treatment of long bone fracture, the bone plate is rigidly affixed along the longitudinal length of the long bone to prevent motion between the fragments. For example, as shown in U.S. Pat. No. 5,702,399 to Kilpela et al., a bone plate is secured to a bone by cables looped around the bone.
Upon installation, the external forces applied to the bone plate are not limited to one particular plane and there may be simultaneous forces in several planes. Thus, a plate which is usually flattened on one or more surfaces will not bear loads equally in all directions and may be adequate to withstand forces in one direction but inadequate to withstand forces in another. For example, a bone plate can adequately withstand compressive and tensile forces along its longitudinal length, substantially preventing movement of the bone fracture. However, a bone plate can be inadequate in withstanding torsional forces, allowing movement of the bone fracture under such loading.
There therefore exists a need for an improved method and device for long bone fracture fixation.